Static random access memory (SRAM) is a type of semiconductor memory that uses bi-stable latching circuitry to store each bit in a memory array. SRAM maintains data in the memory array without the need to be refreshed when powered, but is still volatile such that data is eventually lost when the memory is not powered. Power gating and voltage retention techniques are commonly implemented to the memory array to reduce power consumption. For example, power gates may be used to turn off memory periphery items in a deep sleep mode, and both the periphery items and the memory array in a shut down mode.
When the memory comes out of the shut down mode, power gates are used to ramp up the internal supply voltage of the memory. This can result in a large wake up inrush current.